The term “chiropractic” means “hand action” and is a combination of Greek words “Chiro” (“hand”) and “Prakticos” (“action”). As indicated by its name, in the field of chiropractic, palpation using various parts of the hands, such as a fingertip and the pisiform bone, is performed on the body of a patient for determining a target site for chiropractic treatment, and then chiropractic treatment is performed by a method in which a thrust (i.e., an impact of high speed and low amplitude) is applied to the target site by using various parts of the hands or by using an apparatus employing spring resilience or electromagnetic force. In the field of chiropractic, amelioration of various diseases and ailments is achieved by applying an appropriate thrust to the cranium, the spine, the lumbar vertebrae, the pelvis, and/or joints of limbs so as to correct small dislocation of these bones. (In the field of chiropractic, such small dislocation of bones is called “subluxation” or “misalignment”.) When a portion, to be given a thrust, of the body surface of the patient has a skin slack, the thrust applied is disadvantageously absorbed by the skin slack, thus making it impossible to transmit a satisfactory level of force of thrust to the target site; therefore, generally, before the application of a thrust to the body surface of the patient, the skin of the portion, to be given a thrust, of the body surface of the patient is pulled so as to be placed under tension to remove any skin slack. Also, when a target site for chiropractic treatment is present under a thick layer of fat or muscle, it is a general practice that, in addition to pulling and tensioning the skin of the body surface of the patient to remove a skin slack, a preload is applied to the body surface and the subcutaneous tissue by a method in which either a portion (to be used for applying a thrust) of a hand of the chiropractic practitioner or a forward end portion of a chiropractic apparatus is rather strongly pressed onto the body surface of the patient in the depthwise direction of the body of the patient, thereby increasing the body tissues' ability to allow the propagation of a thrust therethrough. By applying a satisfactory force of preload to the body surface and the subcutaneous tissue of the patient to thereby increase the body tissues' ability to allow the propagation of a thrust therethrough, a chiropractic treatment can be performed even using a relatively small force of adjustment.
In the field of chiropractic, the term “thrust” covers any type of mechanical pressures. As a method for applying a mechanical pressure, there can be mentioned a method in which a fingertip of a chiropractic practitioner or a forward end of a rod (made of a plastic or metal) is placed on the body surface of a patient, and then the fingertip or rod is macroscopically moved to apply a pressure (thrust) to the body surface of the patient. This method is employed in the case where a thrust is applied by using the body of a chiropractic practitioner or the case where a thrust is applied by using a so-called “activator” described below. As another method for applying a mechanical pressure, there can be mentioned a method in which a forward end of a rod (made of a plastic or metal) is placed on the body surface of a patient, and then a mechanical impulse is applied to a rear end of the rod (which is not macroscopically moved) thereby generating a thrust in the form of a pressure wave propagating from the rear end to forward end of the rod to thereby apply a pressure (thrust) to the body surface of the patient. In general, this method is employed only in the case where there is used an apparatus for performing a so-called “Atlas Orthogonal Technique” described below.
In the field of chiropractic, chiropractic treatment (application of a thrust) is usually called “adjustment”. Therefore, hereinafter, application of a thrust is frequently referred to as “adjustment”. (In the field of chiropractic, the term “manipulation” may be used as having the same meaning as “adjustment”.) In the field of chiropractic, a portion, to be given a thrust, of the body surface of the patient is usually referred to as a “contact point”. Therefore, hereinafter, a portion, to be given a thrust, of the body surface of the patient is frequently referred to as a “contact point”. With respect to the general information of chiropractic and to the above-mentioned various terms, reference can be made to, for example, Non-Patent Document 1 (“Kairopurakutikku-Gairon (Outline of Chiropractic)”, authored by Seikyo SUZUKI, published by Taniguchi Shoten Publishing Co., Japan, 1987), Non-Patent Document 2 (“Hajimete Manabu Kairopurakutikku-Sukiru-Kihon-Gensoku-Kara Manipyureishon-Sukiru-Made—(Introduction to Chiropractic Skills—from basic principles to manipulation skills)”, authored and edited by David Byfield, translation supervised by Motoaki OTANI, published by IDO-NO-NIPPON SHA INC., Japan, 1999), and Non-Patent Document 3 (“Okai-DC-No Tekunikku-Bukku, Kihon-Hen, Jissen-Kairopurakutikku-Ajasutomento-Tekunikku (Technique Book of Okai DC (Basics) Practical Chiropractic Adjustment Techniques)”, authored by Takeshi OKAI, published by Japan Medical Publishing Co. LTD., Japan, 2004). With respect especially to the term “adjustment”, reference is made to Non-Patent Documents 1 and 3.
When an adjustment is performed using a finger, such as an index finger or middle finger, problems may arise not only in that a burden is imposed on the finger and the wrist of the chiropractic practitioner (chiropractor), thus causing the chiropractor to suffer injuries, but also in that the direction of the thrust is not correct, thus making it impossible to obtain a desired effect on the patient. When it is necessary to apply a high force thrust, the pisiform bone is used in many cases. However, the pisiform bone is less sensitive as compared to a fingertip, and therefore, a high level skill is required to perform a correct adjustment by using the pisiform bone.
For solving these problems accompanying adjustments performed using the human power, adjustments may be performed using equipment (chiropractic apparatuses). In the case of the use of chiropractic apparatuses, a thrust is applied to the patient by using spring resilience or electromagnetic force. Conventional chiropractic apparatuses are described in, for example, U.S. Patent Application Publication No. US 2002/0082532 A1 (Patent Document 1), U.S. Pat. No. 6,379,375 (Patent Document 2), U.S. Pat. No. 6,602,211 (Patent Document 3), U.S. Pat. No. 6,805,700 (Patent Document 4), and Unexamined Japanese Patent Application Laid-Open Specification No. 2009-5892 (Patent Document 5). These chiropractic apparatuses are generally referred to as “activators”, and the chiropractic techniques performed using such chiropractic apparatuses may be referred to as “Activator Methods Chiropractic Technique (AMCT)”. (Further, in the field of chiropractic, chiropractic apparatuses are frequently referred to as “adjusters”, because they are devices used for performing “adjustment”. Therefore, hereinafter, a chiropractic apparatus is frequently referred to as an “adjuster”.)
In the case of any of the above-mentioned conventional chiropractic apparatuses, the forward end of the adjuster means has either the shape of a circle or a polygon each having a relatively large surface area (for example, about 78 mm2 to about 700 mm2) (e.g., a circle having a diameter of about 10 mm to about 30 mm), or the shape of a circle or a polygon each having a relatively small surface area (for example, about 7 mm2 to about 28 mm2) (e.g., a circle having a diameter of about 3 mm to about 6 mm), wherein the circle or polygon of relatively small surface area has therearound a release surface having a predetermined tapering angle. (With respect to the former (i.e., the case of “relatively large surface area”), reference can be made to Patent Documents 1 to 4; and with respect to the latter (i.e., the case of “relatively small surface area”), reference can be made to Patent Document 5.) Such conventional chiropractic apparatuses pose problems as follows. In the case of the former prior art (i.e., the case where the forward end of the adjuster means has the shape of a circle or a polygon each having a relatively large surface area (for example, about 78 mm2 to about 700 mm2) (e.g., a circle having a diameter of about 10 mm to about 30 mm)), there are advantages not only in that a satisfactory force of preload can be applied to the body surface of a patient, but also in that, during the preload, the patient's pain is small and the adjuster means can be stably positioned on the body surface of the patient. However, the former prior art poses problems in that the forward end portion of the adjuster means cannot be guided to a deep region (near to a target bone for adjustment) in the body of the patient, and a thrust cannot be correctly applied to a small-area target site in the target bone. On the other hand, in the case of the latter prior art (i.e., the case where the forward end of the adjuster means has the shape of a circle or a polygon each having a relatively small surface area (for example, about 7 mm2 to about 28 mm2) (e.g., a circle having a diameter of about 3 mm to about 6 mm), wherein the circle or polygon has therearound a release surface having a predetermined tapering angle), there are advantages not only in that the forward end portion of the adjuster means can be guided to a deep region in the body of the patient, but also in that a thrust can be correctly applied to a small-area target site in the target bone. However, the latter prior art poses problems in that, during the preload, the patient's pain is great and it is possible to cause damage to the body surface tissue of the patient. For these reasons, in the case of the use of the above-mentioned conventional chiropractic apparatuses, performing a safe, correct and effective adjustment is not easy even for a skilled chiropractor.
There is known “Atlas Orthogonal Technique” (AOT), which is a subfield of chiropractic. In the Atlas Orthogonal Technique, the target of an adjustment is limited to the first cervical vertebra (the atlas), i.e., C1. In the case of the Atlas Orthogonal Technique, a large-sized, floor-mounted machine specialized for adjusting the atlas is used. In this large-sized, floor-mounted machine, a chiropractic apparatus (adjuster means) is attached to a movable arm which can hold the chiropractic apparatus stably. In this case, generally, the forward end of the adjuster means has the shape of a circle having a relatively small surface area (for example, a circle having a surface area of about 7 mm2; that is, a circle having a diameter of about 3 mm). In the case of the use of this large-sized machine, by virtue of the fact that the chiropractic apparatus can be held stably, a skilled chiropractor can perform an adjustment of the atlas safely and relatively easily. The main reason for this is that with respect to the subcutaneous tissue around the atlas of a patient, the thickness of the fat and muscle layers therein is not great and, therefore, the forward end portion of the adjuster means can be easily guided to a region near to the atlas simply by placing relatively lightly the forward end portion of the adjuster means on the body surface of the patient. However, this large-sized machine is specialized for adjusting the atlas and cannot be used for an adjustment of a bone other than the atlas.
A chiropractic apparatus which can solve the above-mentioned problems accompanying the prior art has not yet been developed.    [Patent Document 1] U.S. Patent Application Publication No. US 2002/0082532 A1    [Patent Document 2] U.S. Pat. No. 6,379,375    [Patent Document 3] U.S. Pat. No. 6,602,211    [Patent Document 4] U.S. Pat. No. 6,805,700    [Patent Document 5] Unexamined Japanese Patent Application Laid-Open Specification No. 2009-5892    [Non-Patent Document 1] “Kairopurakutikku-Gairon (Outline of Chiropractic)”, authored by Seikyo SUZUKI, published by Taniguchi Shoten Publishing Co., Japan (1987)    [Non-Patent Document 2] “Hajimete Manabu Kairopurakutikku-Sukiru-Kihon-Gensoku-Kara Manipyureishon-Sukiru-Made—(Introduction to Chiropractic Skills—from basic principles to manipulation skills)”, authored and edited by David Byfield, translation supervised by Motoaki OTANI, published by IDO-NO-NIPPON SHA INC., Japan (1999)    [Non-Patent Document 3] “Okai-DC-No Tekunikku-Bukku, Kihon-Hen, Jissen-Kairopurakutikku-Ajasutomento-Tekunikku (Technique Book of Okai DC (Basics) Practical Chiropractic Adjustment Techniques)”, authored by Takeshi OKAI, published by Japan Medical Publishing Co. LTD., Japan (2004)